Yes and no. The main issue is the polling rate within the FRAPS utility when it comes to polling framerates. You see, if it logged framerates at the same speed it does frame TIMES, the results would be much more accurate. Remember, there is a distinct difference between Frames per SECOND and framerate / frame times.

Essentially, frame times can translate directly into framerates but frames per second simply averages out the framerates throughout a second to give a global result of a certain period of time.

What do you think about a metric that measured how completely a frame is rendered? Some threshold below which a frame would not count in the fps number?